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dpb

On 1/30/2012 9:44 AM, wrote:
On Jan 30, 10:43 am, wrote:
The only mistake I made in the original post is, I will attach the
equipment ground to the ground lugs on the disconnect box.

Yes, this is a box I have kicking around. Lessons learned: do NOT
fuse neutral, fuses don't mitigate lightning.

My original problem was, the lathe does not have an on/off switch,
just a plug. I dislike leaving it plugged in all the time because of
lightning, and I want a more convenient way to switch it on.
Thought this was the proper way to do it, except with a 120V
disconnect, which is harder to find. Maybe this is just a waste of
effort like one of the posters said. How about just wiring the
lathe on a residential 20A wall switch?

The motor is 2hp BTW.

It would be pretty likely a 2 hp motor would be dual-voltage.

2 hp @120V would possibly be drawing 22-25 A which is marginal at best
on 20 A circuit.

I'd suggest the better thing is to

a) Convert it to 240 V (halving the current draw), and

b) Add a switch to the device itself.

As for the lightning concern, the likelihood of it being the target of
anything bad is quite low in comparison to things like electronics, a
fridge in restart mode at the time, etc., etc., etc., ... A plain ol'
'lectric motor on its own is pretty robust.

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